SE Android | 8c48de1 | 2012-01-24 05:27:18 -0800 | [diff] [blame] | 1 | |
| 2 | /* Author : Stephen Smalley, <sds@epoch.ncsc.mil> */ |
| 3 | |
| 4 | /* FLASK */ |
| 5 | |
| 6 | /* |
| 7 | * Implementation of the double-ended queue type. |
| 8 | */ |
| 9 | |
| 10 | #include <stdlib.h> |
| 11 | #include "queue.h" |
| 12 | |
| 13 | queue_t queue_create(void) |
| 14 | { |
| 15 | queue_t q; |
| 16 | |
| 17 | q = (queue_t) malloc(sizeof(struct queue_info)); |
| 18 | if (q == NULL) |
| 19 | return NULL; |
| 20 | |
| 21 | q->head = q->tail = NULL; |
| 22 | |
| 23 | return q; |
| 24 | } |
| 25 | |
| 26 | int queue_insert(queue_t q, queue_element_t e) |
| 27 | { |
| 28 | queue_node_ptr_t newnode; |
| 29 | |
| 30 | if (!q) |
| 31 | return -1; |
| 32 | |
| 33 | newnode = (queue_node_ptr_t) malloc(sizeof(struct queue_node)); |
| 34 | if (newnode == NULL) |
| 35 | return -1; |
| 36 | |
| 37 | newnode->element = e; |
| 38 | newnode->next = NULL; |
| 39 | |
| 40 | if (q->head == NULL) { |
| 41 | q->head = q->tail = newnode; |
| 42 | } else { |
| 43 | q->tail->next = newnode; |
| 44 | q->tail = newnode; |
| 45 | } |
| 46 | |
| 47 | return 0; |
| 48 | } |
| 49 | |
| 50 | int queue_push(queue_t q, queue_element_t e) |
| 51 | { |
| 52 | queue_node_ptr_t newnode; |
| 53 | |
| 54 | if (!q) |
| 55 | return -1; |
| 56 | |
| 57 | newnode = (queue_node_ptr_t) malloc(sizeof(struct queue_node)); |
| 58 | if (newnode == NULL) |
| 59 | return -1; |
| 60 | |
| 61 | newnode->element = e; |
| 62 | newnode->next = NULL; |
| 63 | |
| 64 | if (q->head == NULL) { |
| 65 | q->head = q->tail = newnode; |
| 66 | } else { |
| 67 | newnode->next = q->head; |
| 68 | q->head = newnode; |
| 69 | } |
| 70 | |
| 71 | return 0; |
| 72 | } |
| 73 | |
| 74 | queue_element_t queue_remove(queue_t q) |
| 75 | { |
| 76 | queue_node_ptr_t node; |
| 77 | queue_element_t e; |
| 78 | |
| 79 | if (!q) |
| 80 | return NULL; |
| 81 | |
| 82 | if (q->head == NULL) |
| 83 | return NULL; |
| 84 | |
| 85 | node = q->head; |
| 86 | q->head = q->head->next; |
| 87 | if (q->head == NULL) |
| 88 | q->tail = NULL; |
| 89 | |
| 90 | e = node->element; |
| 91 | free(node); |
| 92 | |
| 93 | return e; |
| 94 | } |
| 95 | |
| 96 | queue_element_t queue_head(queue_t q) |
| 97 | { |
| 98 | if (!q) |
| 99 | return NULL; |
| 100 | |
| 101 | if (q->head == NULL) |
| 102 | return NULL; |
| 103 | |
| 104 | return q->head->element; |
| 105 | } |
| 106 | |
| 107 | void queue_destroy(queue_t q) |
| 108 | { |
| 109 | queue_node_ptr_t p, temp; |
| 110 | |
| 111 | if (!q) |
| 112 | return; |
| 113 | |
| 114 | p = q->head; |
| 115 | while (p != NULL) { |
| 116 | temp = p; |
| 117 | p = p->next; |
| 118 | free(temp); |
| 119 | } |
| 120 | |
| 121 | free(q); |
| 122 | } |
| 123 | |
| 124 | int queue_map(queue_t q, int (*f) (queue_element_t, void *), void *vp) |
| 125 | { |
| 126 | queue_node_ptr_t p; |
| 127 | int ret; |
| 128 | |
| 129 | if (!q) |
| 130 | return 0; |
| 131 | |
| 132 | p = q->head; |
| 133 | while (p != NULL) { |
| 134 | ret = f(p->element, vp); |
| 135 | if (ret) |
| 136 | return ret; |
| 137 | p = p->next; |
| 138 | } |
| 139 | return 0; |
| 140 | } |
| 141 | |
| 142 | void queue_map_remove_on_error(queue_t q, |
| 143 | int (*f) (queue_element_t, void *), |
| 144 | void (*g) (queue_element_t, void *), void *vp) |
| 145 | { |
| 146 | queue_node_ptr_t p, last, temp; |
| 147 | int ret; |
| 148 | |
| 149 | if (!q) |
| 150 | return; |
| 151 | |
| 152 | last = NULL; |
| 153 | p = q->head; |
| 154 | while (p != NULL) { |
| 155 | ret = f(p->element, vp); |
| 156 | if (ret) { |
| 157 | if (last) { |
| 158 | last->next = p->next; |
| 159 | if (last->next == NULL) |
| 160 | q->tail = last; |
| 161 | } else { |
| 162 | q->head = p->next; |
| 163 | if (q->head == NULL) |
| 164 | q->tail = NULL; |
| 165 | } |
| 166 | |
| 167 | temp = p; |
| 168 | p = p->next; |
| 169 | g(temp->element, vp); |
| 170 | free(temp); |
| 171 | } else { |
| 172 | last = p; |
| 173 | p = p->next; |
| 174 | } |
| 175 | } |
| 176 | |
| 177 | return; |
| 178 | } |
| 179 | |
| 180 | /* FLASK */ |